Suspected DUI drivers caused two major head‑on crashes this Labor Day weekend in Sonoma County, injuring a total of five people, the CHP said.

Law enforcement agencies focused on impaired drivers over the long weekend and leading into the holiday. Santa Rosa police said it arrested 40 people on suspected DUI and related charges between Aug. 17 and Sept. 3.

CHP arrested 16 suspected impaired drivers from Friday evening to Monday morning.

One arrest came Sunday afternoon following a River Road crash near Korbel Winery. Sean Grant, 54, of San Francisco, had been driving east about 3:45 p.m. when he crossed double yellow lines into the westbound lane to pass a vehicle, CHP Officer Kimberly Lemons said in a news release.

Grant’s two‑seater 2009 Smart Fortwo hatchback hit a 2015 Hyundai Accent. Grant suffered major injuries and was taken to Santa Rosa Memorial Hospital, where he was arrested but released to the hospital because of his injuries.

Hyundai driver Dylan Limber, 27, of Santa Rosa, and his passenger, Samantha Phillips, 30, of Santa Rosa, suffered minor injuries. They were taken to Santa Rosa’s Kaiser Permanente Medical Center.

On Saturday, another driver caused a serious crash on Old Redwood Highway near Shiloh Road in Windsor after his 2005 Mitsubishi Spider crossed the double yellow lines, Lemons said. George Varela, 47, of Windsor, was heading north about 6:30 a.m. when he attempted to pass another car and struck a southbound car, seriously injuring its driver, Elizabeth Bradshaw, 61, of Santa Rosa.

Bradshaw was taken with major injuries to Santa Rosa Memorial Hospital.

Varela, who also was taken to the hospital and treated for minor injuries, was arrested on suspicion of DUI and drug possession, Lemons said. Varela was booked into the Sonoma County Jail.

The injured drivers’ conditions weren’t available Tuesday.

You can reach Staff Writer Randi Rossmann at 707‑521-5412 or randi.rossmann@pressdemocrat.com. On Twitter@rossmannreport.